When a motor boat which has an outboard drive unit, such as an inboard/outboard motor boat, is transported by means of a trailer or the like, it is necessary to maintain the outboard drive unit in a tilted-up position, in order to avoid damage to the drive unit.
Devices are employed which engage the drive unit to retain the outboard drive unit in a tilted condition. Some of these devices are tension devices which attach to the device unit and to another element. Also in the prior art, rigid brace members have been employed which engage the trailer and the drive unit or which engage the drive unit and the transom of the boat.
The following show prior art devices for retaining a boat propeller drive unit in a tilted-up position: Holsclaw U.S. Pat. No. 2,901,267, dated Aug. 25, 1959; Anderson U.S. Pat. No. 2,939,670, dated June 7, 1960; Driscoll U.S. Pat. No. 3,693,576, dated Sept. 26, 1972; Patterson U.S. Pat. No. 3,941,344, dated Mar. 2, 1976; Wells U.S. Pat. No. 3,952,986, dated Apr. 27, 1976; Saver U.S. Pat. No. 4,125,236, dated Nov. 14, 1978; Espes U.S. Pat. No. 4,331,431, dated May 25, 1982.
Devices of the type disclosed in the aforementioned patents have not proven satisfactory due to the fact that the trailer is one of the elements engaged by the device. This condition is objectionable due to the fact that relative movement between the boat and the trailer during travel creates a strain between the boat and the drive unit.
Another prior art patent is Brown et al, U.S. Pat. No. 2,977,084, dated Mar. 28, 1961. This patent shows a brace element between the transom of the boat and the propeller drive unit. Such a connection is objectional due to the fact that relative movement between the boat and the drive unit may occur, and such movement creates a strain on the drive unit.
Other known safety devices are employed which rely upon tension forces, rather than compression forces, in retaining the outboard drive unit in the tilted "up" position. For example, in one known device a strap with a hook on each end thereof is connected to the drive shaft housing and to the propeller drive unit. Such devices are not satisfactory in that forces which tend to tilt the drive unit downwardly also tend to straighten out the hooks on the ends of the strap. The hooks release when they approach a straight condition.
It is accordingly an object of this invention to overcome the deficiencies in known devices for retaining a boat propeller drive unit in a tilted-up position and to provide a retention device for a propeller drive unit in which there is a positive firm force to maintain the propeller drive unit in a tilted-up position.
It is another object of this invention to provide a novel retention device for a boat propeller drive unit, such as for an inboard/outboard propeller drive unit, which is a single sturdy, rigid device, and which is easily and readily placed into proper position for use.
Another object of this invention is to provide such a retention device which can be produced at relatively low costs and which is long-lived.
Other objects and advantages of this invention reside in the construction of parts, the combination thereof, the method of production, and the mode of operation, as will become more apparent from the following description.